Add optimized Makefile support for SoCFPGA handoff

- Introduce socfpga_g5_handoff_prepare target in U-Boot
  arch/arm/mach-socfpga/config.mk
- Users can convert the handoff via make prepare.
- Detects Altera/Intel SoCFPGA boards from .config
- Combines vendor/board extraction into a single shell call
- Checks for hps_isw_handoff folder and .hiof files
- Uses ls -d instead of find for faster folder detection
- Runs BSP generator script only if files exist
- Non-blocking: continues if handoff folder or files are missing
- HANDOFF_PATH user define allows overriding auto-detected folder
- Minimizes subshells and other slow constructs for faster CI

Signed-off-by: Brian Sune <briansune@gmail.com>

arch/arm/mach-socfpga/config.mk

@@ -0,0 +1,48 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Brian Sune <briansune@gmail.com>
+
+ifeq ($(CONFIG_TARGET_SOCFPGA_CYCLONE5),y)
+archprepare: socfpga_g5_handoff_prepare
+else ifeq ($(CONFIG_TARGET_SOCFPGA_ARRIA5),y)
+archprepare: socfpga_g5_handoff_prepare
+endif
+
+socfpga_g5_handoff_prepare:
+	@SOCFAMILY="$(SOCFAMILY)"; \
+		if [ -z "$$SOCFAMILY" ]; then \
+			exit 0; \
+		fi; \
+		echo "[INFO] SOC family detected: $$SOCFAMILY";
+		@set -- $$(awk -F'"' ' \
+		    /^CONFIG_SYS_VENDOR=/ {v=$$2} \
+		    /^CONFIG_SYS_BOARD=/ {b=$$2} \
+		    END {print v, b}' .config); \
+		VENDOR=$$1; \
+		BOARD=$$2; \
+		if [ -z "$$VENDOR" ] || [ -z "$$BOARD" ]; then \
+			exit 0; \
+		fi; \
+		BOARD_DIR=$(src)/board/$$VENDOR/$$BOARD; \
+		if [ "$$HANDOFF_PATH" ]; then \
+			echo "[INFO] Using manually specified handoff folder: $$HANDOFF_PATH"; \
+		else \
+			HANDOFF_BASE=$$BOARD_DIR/hps_isw_handoff; \
+			if [ ! -d "$$HANDOFF_BASE" ]; then \
+				exit 0; \
+			fi; \
+			HANDOFF_PATH=$$(ls -d "$$HANDOFF_BASE"/*/ 2>/dev/null | head -n1); \
+			if [ -z "$$HANDOFF_PATH" ]; then \
+				exit 0; \
+			fi; \
+			echo "[INFO] Auto-detected handoff folder: $$HANDOFF_PATH"; \
+		fi; \
+		HIOF_FILE=$$HANDOFF_PATH/$$(basename $$HANDOFF_PATH).hiof; \
+		if [ ! -f "$$HIOF_FILE" ]; then \
+			echo "[WARN] No .hiof file found in $$HANDOFF_PATH, skipping BSP generation."; \
+			exit 0; \
+		fi; \
+		echo "[INFO] Found hiof file: $$HIOF_FILE"; \
+		echo "[INFO] Running BSP generator..."; \
+		python3 $(src)/tools/cv_bsp_generator/cv_bsp_generator.py -i "$$HANDOFF_PATH" -o "$$BOARD_DIR/qts" || echo "[WARN] BSP generator failed, continuing..."; \
+		echo "[DONE] SoCFPGA QTS handoff conversion complete."